An electrical system for a modern motor vehicle, among other items includes; a battery, an alternator, a regulator and a myriad of motors, sensors, computers, lights and other electronic devices which are interconnected with wiring. These electronic devices draw varying amounts of electrical current depending upon their function and how they are being utilized. The alternator/regulator assembly generates electrical current by converting rotational energy into electrical energy. An engine, typically through pulleys and belts, supplies the rotational energy to the alternator/regulator assembly. Therefore, whenever the engine is running, the alternator is rotating.
The torque required to rotate the alternator is proportional to the current that it is producing. A sudden increase in current production and the associated increase in torque required to rotate the alternator is significant enough to cause the engine speed to reduce by a few hundred RPM. These changes in engine RPM are perceived as poor idle quality and can cause a drop in fuel economy. It may be desirable to minimize the changes in engine RPM. Accordingly, there is a need for improvements in the art of alternator control.